Argentina has finally run out of wiggle room in a billion-dollar showdown over foreign debts unpaid since the country's world-record default a decade ago.

BUENOS AIRES, Argentina -- Argentina has finally run out of wiggle room in a billion-dollar showdown over foreign debts unpaid since the country's world-record default a decade ago, and the stakes couldn't be higher for President Cristina Fernandez.

Late Wednesday night, a federal judge in New York ordered Argentina to pay immediately and in full everything it owes to what she calls "vulture funds" that she blames for much of her country's troubles. That adds up to $1.3 billion, due by Dec. 15.

The judge also barred Argentina from paying other bondholders until it satisfies this judgment, putting the president's back against the wall: If she doesn't reverse her longstanding position and pay up, she risks triggering another historic Argentine debt default, this time totaling more than $20 billion.

"It is hardly an injustice to have legal rulings which, at long last, mean that Argentina must pay the debts which it owes. After ten years of litigation this is a just result," U.S. District Judge Thomas Griesa concluded.

Argentina's government did not immediately respond to Griesa's orders, delivered just before the long Thanksgiving holiday closed markets in New York until Monday.

Sen. Augustin Rossi, who leads the ruling party's bloc in Congress, said in a local radio interview Thursday that he personally thinks Argentina's government would be within its rights to reject it, "on behalf of all the Argentines, after we've made such an enormous effort to get out of default."

Argentina's president and economy minister insisted earlier this week that they won't pay a single dollar to the plaintiffs, and said they would appeal to the U.S. Supreme Court. But the judge gave Fernandez no room to maneuver meanwhile, lifting his stay and ordering that the money be put in an escrow account for the plaintiffs to collect.

"These threats of defiance cannot go by unheeded," the judge wrote. "The less time Argentina is given to devise means for evasion, the more assurance there is against such evasion."

If Fernandez refuses, the judge said that the Bank of New York ( BK), which processes Argentina's bond payments, will find itself in violation if it doesn't hold up payments to all other bondholders.